Processes apparatuses are known in which liquids are subjected to a voltage field, as a result of which the ions, cations or anions contained in the liquid are separated from one another and/or are precipitated in extremely fine dispersion as a solid precipitate. Often the liquid is passed through an ion exchanger in addition to the electrolytic process in order to increase the throughput rate of purified liquid. In that process solid materials are also precipitated. The increase in the purified volume makes possible the continuous performance of the ion exchange process, without the liquid flow having to be interrupted.
An apparatus exploiting this combination of the electrolytic and chemical process principle is described in German Patent Application 3,341,242, in which oxygen is removed from an aqueous solution electrochemically. In this application, the liquid flow is passed through a permeable, spatially extending ion exchanger. At the same time, the liquid flow is subjected to a voltage field which propagates radially from concentrically disposed electrodes and extends coaxially with respect to the liquid flow. The oxygen produced in the ion exchange process is removed via pipes.
German Patent Application 3,805,813, discloses a loaded ion exchange material which can be retreated electrolytically, chemically or electrochemically, without having to be removed from the apparatus. In that case, the ion exchange material is subjected, for example, to a pulsating alternating voltage field or ionizing chemicals.
Common to all these processes and apparatuses is that the precipitating solid material remains in the liquid flow. As a result, it is possible that this material will revert to the original state in a subsequent, even unintended, chemical or electrochemical process and exhibit its harmful or undesirable effect.
Furthermore, it is not possible in the case of the known apparatus to reduce cations and anions with the same ion exchanger material.